Underreamer



W. H. HAZLE'IT May 17,1932. U m Re. 18,473

2 Sheets-Sheet 1 Original Filed 001:. 23, 1924 fizz-aw? v Reissued May 17, 1932 UNITED STATES PATENT OFFICE WALTER H. HAZLETT, OF LOS ANGELES, CALIFORNIA, ASSIGNOR, BY DIRECT AND HESNE ASSIGNMENTS,-TO JOHN GRANT, OF'LOS .ANGELES, CALIFORNIA unnmnamnn Original 110. 1,674,040, dated June 18, 1928, Serial No. 745,324, filed October 23, 1924. Application for reissue filed June 1, 1931. Serial No. 541,479.

My invention relates to the art of drilling oil wells, and is particularly applicable to the drilling of oil wells by'what is known circulated serves to carry upwardly with it the cuttings from the bit, and also serves to cement and mud-up the walls of the hole, so that they will stand without the necessity of casing, it being very common to drill holes in excess of QOOOi'eet deep by the rotary method without the use of any casing whatever, the rotary mud under pressure serving to hold up the walls of the well and make such drillin Y possible.

it is not the usual practice in drilling with the rotary method to carry pipe, that is to say, it is not the practice to suspend in the well a string of casing through which the drill values of carrying casing is to prevent the well from caving during the time the drill pipe and bit are being withdrawn. This necessitates the use of a bit which will pass readily through the casing and which will, therefore, drill a hole either smaller or of approximately the same diameter as the in side of the carried casing. Casing cannot pass through a hole of smaller diameter than its outside diameter, and the practice of mud is rill pipe carrying casing in rotary drilling has never been generally adopted.

It isan object of'my invention, however, to provide an underreamer which may be collapsed in such a manner as to pass readily through the casing-but which automatically expands as it leaves the casing sothat it will drill a hole somewhat larger than the'outside diameter of the casing. a

It is a further object of my invention to provide such an underreamer whichcan be readily-drawn upwardly into the casing for withdrawal from the well, said underreamer being collapsed for this purpose.

It is a further object of the invention to provide a novel form of oscillating cutting device which, while a plicable to this particular field, may also be used on other types of bit or reamer.

It is a further object of the invention to provide a novel means for operating the cutting member of the device.

It is a still further object of the invention to provide a thrust receiving'member.

Other objects and advantages of the in vention will be made evident hereinafter.

Referring to the drawings which are for illustrative purposes only, and in which I show a preferred form of my invention.

Fig. 1 is a vertical view of a device employing the features of my invention, this view being partially in section and showing the disposal of the parts when the device is in non-operating or retracted position.

Fig. 2 is a sectional view similar to Fig. 1, this view showing the disposal of the parts of the device when the underreamer is in operating or reaming disposal.

Fig. 3 is a section taken as indicated by the line 33 of Fig. 1.

Fig. 4 is an enlarged fragmentary sectional view showing the novel locking means employed in this embodimentof my invention.

Fig. 5 is a section taken as indicated by the line 55 of Fig. 2. Y

Fig. 6 is a sectional view taken as indicated by the line 66 of Fig. 2. Y v

Fig. 7 is a sectional view taken as indicated by the line 77 of Fig. 2.

- guide 19 extending between the lower edge socket 34 of the bit 32.

- plo un In the drawings I show my invention as comprising a body 11 havin a threaded pin 12 formed at the upper end t ereof. This pin 1 12 is arranged for attachment to a tool joint 13 which is in turn attached to the lower end of a string of drill pipe (not shown). An upper bearing or cam portion 16 is formed on the body '11, this cam portion 16 being cylindrical in shape, as shown, and being arranged eccentrically with respect to the central axis A-A of the body 11', and so located as to move in a circular path similar to that of a crank, when the body 11 is rotated. Below the upper cam 16 is formed an upper concentric bearing portion 18, this concentric portion 18 havin an axis coincidin with the axis AA of t e body 11. A ongitudi-' nally angled guiding cam face 19 is provided, as clearly shown in Figs. 1 and 2, this of theu'pper cam 16 and the upper edge of t e upper concentric portion 18. At the lower end of the body 11 I provide a lower -con-. centric bearing portion 21 which has an axis coinciding with the axis AA of the body 11. Between the upper and lower concentric portions 18 and 21 I provide a lower bearing or cam 23, this cam 23 being cylindrical in shape and being disposed so that the center line thereof is eccentric with respect to the axis A-A of the body 11. The axis of the upper cam.16,is indicated at 25 in the drawings, and the axis of the lower cam- 23 is indicated at 26. From the drawings it will be seen that the centers. of the upper and lower cams are disposed on opposite sides .of the axis A-A and at equal distances therefrom. -The lower cam 23 is provided b formin an eccentric'face 27 and by providing a filer piece 28, as shown in Fi s. 2 and 6, this filler piece being secured in p ace means of akey 29. The purpose of the filler piece 28 is to build upv the lower cam 23 so that the outer face thereof will be cylindrical. The filler piece 28 provides a lower longitudinall of the body 11, the lower threaded end 33 of the body 11 being threadedl secured in the f the reaming construction is to b'e'employed in combination with a bit, this arrangement is emed. However, if 'it is intendedfor the erreamingconstruction to be employed as an underreamer only, a suitable guiding nose member may be substituted for the bit A. retaining member 36 which com rises a cylindrical body having a cylindrica opening 37 is placed on the upper cam 16, this retaining member 36 havin centralizing lugs 38, as shownin Fig. 3. hen the device is angled guiding cam' face 31 which exten s as shown in Fig. 2.

- A bit 32 may be secured to thelower end in non-operating position, the retaining ring 36 is situated on the lower end of" the cam 16; and when the device is'in operating position, the retaining member 36 is situated at the upper end of the upper cam 16, as shown in Fig. 2. For locking the retaining member 36 in its lowermost or non-operating position, I provide a lock construction, as is sition, a spring 44 is provided which is situ- I ated in the opening 41 and bears against the flange 43, as shown. The plunger 40 has a central opening 46 into which the cylindrical portion 47 of a loc 'ng. pin 48, having a head 49, extends. The pin 48 is retained in theopening 46 bymeans of a bar 50 which extends into slots 51 of the plunger 40. A spring 52 is provided for resiliently retains ing t A cap 53 is secured to the outer end of the plunger 40, as indicated by the threadeden e locking pin 48 in locking position. I

gagement 54 in Fig. 4. When the plunger is in locking position, the head 49 of the locking pin 48 is forced into a locking opening 56 formed in the upper cam 16. The head 49, as shownfis provided with a beveled edge so that a side pressure thereagainst will not prevent the removing of the pin from the opening 56 when the plunger is allowed to T move outwardly into non-locking position, it

beingreadily seen that engagement between the beveled face and the opening 56 tends to force the pin 48 outwardly. When the dewell, thelugs 38 engage with the internal face of the Well casing 58, and the cap 53 engages with the inner-face of the casing 58,

being: retained in looking position or in such 48 and the plunger 40, it is possible to depress the plunger 40 even though the pin. 48 is not aligned w'th the opening 56. It will be seen that in this case'a relative movement between the plunger and the pin will occur. This makes it possible for the plunger and cap40 and 53, respectively to be depressed during the elevating of the under reamer. I

'I rovide a thrust receivin member 60 whicii has a cylindrical outer ace 61 which is beveled at 62, and which has a concentric central opening 65. When the device is in its collapsed or non-operating position, the thrust receiving member 60 is situated on the lower concentric portion 18 and is positioned .vice 'is being lowered to the bottom of the so as to be concentric to the axis AA of the body 11, as shown in Fig. 1. When the device is in operating position, the thrust receiving member is disposed on the upper cam 16 in the position shown in Fig. 2. Below the thrust receiving member 60 I provide an intermediate spacing member 67, which has a bore 68 and an upper lip 69. When the device is. in its collapsed position, this intermediate member 67 is positioned on the lower cam 23, as shown in Fig. 1; and when the device is in operating position, the intermediate member 67 moves upwardly and hecomes journaled on the-upper concentric portion 18, as shown in Fig. 2. The upper face of this intermediate member engages with the lower face of the thrust member 60.

A cutter member 71 comprises a cylindrical body having an outer cylindrical face 72 which is beveled at 73, as shown, and has a cylindrical concentric bore 75. The outer face 72 is serrated so as to provide cutting teeth 76, as shown in the drawings. The cutter 71 is positioned on the lower concentric portion 21 when the device is in its collapsed position, and it journals on the lower cam 23 when the device is in its expanded or reaming position. A driver 77 is provided in the form of a ring or collar. 7 8 which slides on the lower concentric portion 21. Threadedly secured to the ring 78 and extending downwardly therefrom is a skirt 79, this skirt having an inner face 80 which engages with the cylindrical face 81 of the head of the bit 32. Compressed between the upper shoulder 83 of the bit 32 and the lower shoulder 84 of the collar .78 is a coil spring 85 which exerts an upward resilient pressure a ainst the driver 77. The purpose of this river member 77 is to translate the movable parts described, to their upper-or operating positions and to yieldingly retain them in such positions.

, Rotary mud is supplied to the underreamer through a central passage 87. Connected with the passage 87 is a passage 88, which communicates with an opening 89 in the intermediate member 67, this opening 89 coinciding with the passage 88 when the member 87 is in operating position. A branch 90 is rovided which communicates with an opening 91 in the driver 77 when the driver is in the position shown in Fig. 2, this branch 90 serving to provide lubrication for the cutter member-71. The lower end of the passage 87 is arranged to supply lubricating fluid to the passage 92 of the drill 32, supplying lubrication for the cutting edge thereof.

The operation of the construction just described may be as follows:

When the underreaming bit is to be lowcred into a well, through casing which is suspended therein, the retaining ring 36 is forcedinto retaining position as shown in Fig. 1, this forcing the movab le parts into? their collapsed or non-operatin position, as

shown and previously describe against the action of the driver 77. The cap 53 is then forced inwardly from the position indicated by thedotted lines 95 in Fig. 4 into the full lines of this figure. This forces the head 49 of the locking pin 48 into the opening 56 and retains the retaining member 36 and the other movable parts of the underreamer in nonoperating position. The underreamer is then inserted into theupper end of the well casing, the engagement between the cap 53 and the inner wall of the casing ,58 serving to retain the locking arrangement in locking position, as previously described. The underreamer is then lowered through the casing, the parts being retained in non-operating or collapsed position until the cutting members are below the casing. When the bit leaves the lower end of the casing 58, the cap 53 moves outwardly into theposition shown-in Fig. 2. This removes the locking pin 48 from the opening 56 and allows the movable parts of the device to be moved upwardly into operating or expanded position by the ring so as to slide readily upon the lower,

cam 23. The body 11 is then rotated by a rotary table through the drill pipe, not

shown. This causes the upper and lower.

cams to bodily move through a circular orbit,

the axial centers of the cams 16 and 23 travelling through a cycle as indicated by the .line

98 of Fig. 3. It will be seen that the upper cam 16, as it moves through a cycle indicated by the line 98, bodily moves the thrust receiving member 60 through a similar cycle. Throughout this cycle the thrust receiving member 61 is brought into engagement with the wall of the hole being reamed, as indicated at 99 in Fig. 2. The lower cam' 23, as

it moves throu h a cycle indicated by the line 98, will bo ily. move the-cutter member 71 through a cycle similar to that of the thrust receiving member 60. This brings thecutting teeth 76 and the cutting member 71.

into engagement with the wall of the hole 'bein reamed throughout the cycle, as indicate at 100 in Fig. 2.

It will be seen t and 23- arediametricallg opposed, the points of engagement of the t opposite, and side motion is thereby obviated. I As the bodyll rotates, the cutter 7'1 has a rolling engagement with the wall of the rust receiving mom ber 60 and the cutter 71 will be diametrically at owing to the fact thata I the centers of the upper and lower cams 16 parts into nonoperatingiposition, the con hole being reamed, and this engagement will causea breaking away of thewall, most of this breaking away being accom lished by the teeth on the lower beveled face 3, whereas the teeth 7 6 on the cylindrical face 72 serve to smooth and true up the reamed portion of the hole. When the lower beveled face of the cutter 71 wears away, the cutter may be inverted and the upper beveled face 73 made to re lace this lower and worn beveled face, there by cutter and making the life of this cutter 71 substantially twice as lon When the device is to elevated to the surface of the well, it is pulled up. As the retaining ring 36 enters the lower end of the casing 58, the cap 53 will be forced inwardly. This is possible, due to the resilient association between the pin 48 and the plunger 40,

as previously described. The upper beveled face 62 of the thrust receiving ring enages the lower end of the casing 58. This forces the ring downwardly onto. the upper concentric portion 18, which moves this thrust receivin ring60 radially so as to be concentric to the axis of the body, and also forces the movable parts of the device therebelow into nonoperating position as shown in Fig. 1. Owing to the fact that any en- I gagement between the parts of the underreamer and the casing, as it is being moved upwardly therethrough, tends to move these struction will not bind therethrough.

The term underreamer tends to convey the impression that my inventionis solel for the purpose of underreaming for awe l casing which is advanced downwardl into a well as the drilling progresses. I wi to impress, however, that my invention is equally ut will pass freely useful as a reamer which operates continuously with a bit. As an example, in some wells a short surface casing which extends through the Stovepipe casing, is employed for preventing a caving-in of the softer strata near the surface. In removing or inserting the bit and reamer, they must pass throng this surface casin y invention is very suitable for use un er these conditions, owing to the novel means for locking the cutter elements in contracted position while the bitpasses through the casing.

From the foregoing escri tion, it will be seen that a very important eature of this invention is the provision of a cutter which is arranged to be bodily moved longitudinally and radially from a collapsed position to a position to ream a hole. By providing the thrust receiving ring 60, any radial or side motion in the underreamer is entirely counteracted due to the fact that the point of engagement of the thrust receiving ring is at all times diametrically opposite to the engagement of the cutter 71 to the wall of the providing what is equal to a new hole, the novel cam arrangements making this possible.

The ends of the bores in the thrust member and in the cutter preferably have their walls longitudinally angled outwardly to provide a cam surface for cooperation with the guiding cam faces on the body so that these members may more easily slide axially onto the cam portions of the body.

I claim as my invention: V 1. In a rotary underreamer, the combination of: a body having a substantially concentric bearing portion and an adjacent eccentric bearing portion; a rotary cutter nor-- mally positioned on said concentric portion of the body; and means operable to axially translate said cutter from said concentric bearing ortion onto said eccentric bearing rtionor rotation thereon when the body is rotated.

' 2. In a rotary underreamer, the combination of: a body having a substantially concentric bearing portion, an eccentric bearing port-ion and an intermediate longitudinally angled cam face; a rotary cutter normally positioned on said concentric portion of the body; and means operable to axially translate said cutter from said concentric bearing portion to slide over said angled cam face onto said eccentric bearing portion for rotation thereon when the body is rotated.

3. In a rotary underreamer, the combina, tion of: a body having a substantially concentric bearing portion and an eccentric bearing portion longitudinally disposed; a rotary cutter normally positioned on said concentric portion of the body; and means operable to axially translate said cutter from.

upper and lower concentric portions, said cams being diametrically o posed; a thrust receiving member carried y said body; a cutter carried by said bod a retaining member for retaining said thrust receiving member on said upper concentric portion and said cutter on said lower concentric portion; and means for moving said thrust receiving member onto said upper cam and said cutter onto said lower cam, said thrust receiving member and said cutter being moved in radial oscillations by said cams when said body is rotated.

5. In an underreamer, the combination of:

.a body having upper and lower cams and upper and lower concentric portions, said cams being diametrically o posed; a thrust receiving member carried y said body; a

cutter carried by said body; a retaining member for retaining said thrust receiving member on said upper concentric portion and said cutter on said lower concentric portion; a lock for releasably locking said retaining member in retaining position; and means for moving said thrust receiving member onto cams being diametrically opposed; a thrustreceiving member carried by said body; a cutter carried by said body; a retaining member for retaining said thrust receiving member on said upper concentric portion and said cutter on said lower concentric portion; a lock for releasably locking said retaining member in retaining position, saidlock comprising a plunger carried by said retaining member, said plunger being arranged for extension into an opening in said body to lock said retaining member in retaining position, a cap attached to the outer end of said plunger, and a spring for removingsaid plunger from said opening when a pressure on said ca is removed; and means for moving said t rust receiving member onto said upper cam and said cutter onto said lower cam when said lock is released, said thrust receiving member and said cutter being moved in radial oscillations by said cams 1 when saidbody is rotated.

7. An underreamer as defined inclaim 6 in which said plunger is retained in locking position due to engagement between said cap and the casing of a well, said cap being disengaged when said cap moves out of the casing.

, 8. In an underreamer, the combination of:

a body having upper and lower cams and upper and lower concentric portions, said cams being diametrically opposed; a thrust receiving member carried by said body; a cut- ,ter carried by said body; a retaining member for retaining saidthrust receiving member on sand upper concentrlc portion and said cutter on said lower concentric portion; a

driver disposed on said lower concentric portion and engaging said cutter; and means whereby said river is caused to move said thrust receiving member and said cutter on said upper and lower cams respectively, when said lock is released. I

9. An underreamer as defined in claim 4 'in combination with guiding faces for guiding said thrust receiving member and said cutter onto their respective cams.

ID. In an underreamer,-. the combination of: a body having upper and lower cams and upper and lower concentric portions, said cams being diametrically opposed; a thrust receivlng member carrie by said body; a cutter carried by said body; a retaining member for retaining said thrust receiving member on said upper concentric portion and said cutter on said lower concentric portion; an intermediate member disposed between said thrust receiving member and said cutter; and means for moving said thrust receiving member onto said upper cam and said cutter onto said lower cam, said thrust receivin member and said cutters being moved in ra ial oscillations by said cams when said body is rotated.

11. A rotary underreamer body having: a substantially concentric bearing ortion and an adjacent offset eccentric bearing portion longitudinally disposed, the concentric portion forming a bearing for a rotary cutter in collapsed position and the eccentric portion forming a bearing for said cutter in expanded position. a

12. An underreamer body having: a substantially concentric bearing portion, an adjacent oifset eccentric bearinlg portion and aim intermediate longitudinal y angled 'cam ace.

13. An underreamer body having: a su stantially concentric bearing portion and an adjacent offset eccentric bearing portion, said concentric portion having a retaining orifice formed therein. v

, 14. An underreamer body having: two relatively spaced substantially concentric bearing portions, an oifset eccentric bearing portion between said concentric bearing portions, an offset eccentric bearing portion adjacent and above the upper concentric bearing portion, and an abutment shoulder above the upper eccentric bearing portion, the bearing portions being longitudinally disposed and the eccentric portions being oppositely ofl'set transversely.

15. An underreamer body having: two opitcly ofiset relatively spaced eccentric os gearing portions, a substantially concentric bearing portion between said eccentric bearing ortions, and a substantially concentric bearlng portion below the lower eccentric portion, the several bearing portions being longitudinall disposed.

16. An un erreamer body having: two opositely olfset relatively s aced eccentric earing portions, 9. substantlally'concentric bearing ortion between said eccentric bearing portions, a substantially concentric bearing portion below the lower eccentric portion,

and longitudinally angled cam faces connecting each concentric bearing portion with the upper adjacent eccentric bearing portion, the several bearing portions being longitudinally disosed.

1 In a rotaryunderreamer, an arbor having an eccentric portion, a roller cutter on said arbor, said cutter being lengthwise Ill of the arbor shift-able to and from a position bearing on said eccentric bearmg..

18. In a rotary underreamer, a mandrel, a

roller cutter embracing said' mandrel, said cutter being shiftable laterally on and withrelation to said mandrel so as to position it either in projected or retracted position.

Y 19. In a rotary underreamer, a mandrel, a roller cutter journalled thereon about the axis of said mandrel, said mandrel having a laterally oflset journal portion, said cutter being longitudinally movable on said mandrel to position it either ofi or upon said ofiset portion whereby to dispose it in retracted or projected position.

20. In a rotary underreamer, a mandrel, a roller cutter journalled thereon about the axis of said mandrel, said mandrel having a laterally ofiset journal portion, said cutter being longitudinally'movable on said mandrel to position it either of! or upon said offset portion whereby to dispose it in retracted or projected positions, and means urging said cutter upon said ofiset portion.

21. In an underreamer, a mandrel having thereon an ofiset cutter bearing of limited longitudinal extent, and' an annular cutter element surrounding and movable longitudinally on the mandrel and adapted to fit around the offset bearing.

22. In an underreamer, a mandrel having thereon an offset cutter bearing of limited longitudinal extent and having a reduced portion longitudinally adjacent the ofl'set .bearing, and an annular cutter element surroundingand movable longitudinally on the mandrel, adapted to fit closely around the ofiset bearing and to fit loosely around the reduced portion.

23. Ina device of the character described, a mandrel having thereon arelatively enlarged eccentric cylindric bearing of limited longitudinal extent, and an annular roller surrounding and movable longitudinall on the mandrel and having a cylindric ore adapted to fit around the bearing for rotation of the roller thereon.

In an underreamer, a mandrel having lon 'tudinally spaced cylindric parts of relative y larger and smaller diameters, and a rotatable cutter element surrounding the mandrel and having an internal cylindric bearing adapted to fit upon the larger mandrel part when the cutter element is in one longitudinal position and to loosely surround the smaller mandrel part when the cutter element is in another longitudinal position.

25. In an underreamer, a'mandrel having thereon an ofiset cutter bearing of limited longitudinal extent and having a reduced portion longitudinally adjacent the ofiset bearing, a diagonal cutter guiding surface between the reduced portion and the cutter bearing, and an annular cutter element surrounding and movable longitudinally on the mandrel, adapted to fitclosely around the and an annular roller surrounding and movable longitudinally on the mandrel and having a cylindric bore adapted to fit around the bearing for rotation of the roller thereon and adapted to fit loosely around the relatively reduced portion, and the cutter having at the end of its cylindric bore a conical bore part complementary to the conical guiding part on the mandrel.

27. In an underreamer, a mandrel having thereon a plurality of spaced ofl'set bearings oflimited longitudinal extent and having a corresponding number of reduced portions each longitudinally adjacent an offset bearing, a plurality of annular elements surrounding and movable longitudinally on the mandrel, each adapted to fit around one of the offset bearings and to move longitudinal- I 1y between a position on such bearing and a position surrounding the adjacent reduced part, and means pressing longitudinally against oneof the annular elements to move all said elements longitudinally on the mandrel.

28. In an underreamer, a mandrel having thereon a plurality of spaced ofiset bearings of limited longitudinal extent and having a correspondin each longitu 'nally adjacent an ofi'set bear-- ing, one of said reduced portions being located between two of said ofl'set bearings, a plurality of annular elements surroundin and movable longitudinally on the mandre and each adapted in one position to fit around one of the ofiset bearings and to move longitudinally between a position on such bear-' ing and a position surrounding the adjacent reduced part, and an annular spacer surrounding the mandrel and positioned between =two elements, said spacer having a bore large enough to fit over a bearing.

number of reduced portions.

29. In a device of the character described,

a mandrel, an annular roller-element surshiftable rectilinearly laterally on and with relation to said mandrel so as to position it either in projected or retracted position. I

r 32. In. an underreamer, a mandrel having thereon an ofl'set cutter bearing of limited longitudinal extent and a reduced portion longitudinally adjacent the offset portion, a cutter element surrounding and movable longitudinally on the mandrel and adapted a in one position to fit around the oifset bearing and in another position to surround the ad]acent reduced part, and an annular member surrounding the mandrel adjacent the cutter element and movable longitudinally 1 therewith, said member adapted in one part of its length to fit over the offset bearing and in another part of its length to fit over t e reduced part. r WALTER H. HAZLETT. 

